LASER PRECISION, NO HEAT / Petaluma startup zeroes in on a technology that it hopes will spawn a new industry

Tom Abate, Chronicle Staff Writer

Published 4:00 am, Monday, June 18, 2007

Photo: Chris Stewart

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.jpg Event on 6/14/07 in Petaluma.
Greg Spooner (cq), PhD, principal applications engineer at Raydiance, observes as a focused laser beam machines the interior of a glass prism using a Raydiance laser platform. According to the website of the Petaluma company, Raydiance has is developing the world�s first fully software-controlled, desktop-size ultrashort pulse (USP) laser. Photographed June 14, 2007.
Chris Stewart / San Francisco Chronicle Greg Spooner, Raydiance MANDATORY CREDIT FOR PHOTOG AND SF CHRONICLE/NO SALES-MAGS OUT less

.jpg Event on 6/14/07 in Petaluma.
Greg Spooner (cq), PhD, principal applications engineer at Raydiance, observes as a focused laser beam machines the interior of a glass prism using a Raydiance laser ... more

Photo: Chris Stewart

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.jpg Event on 6/14/07 in Petaluma.
Greg Spooner (cq), PhD, principal applications engineer at Raydiance, holds a industrial-grade sapphire with laser micro machining using a Raydiance laser platform. According to the website of the Petaluma company, Raydiance has is developing the world�s first fully software-controlled, desktop-size ultrashort pulse (USP) laser. Photographed June 14, 2007.
Chris Stewart / San Francisco Chronicle Greg Spooner, Raydiance MANDATORY CREDIT FOR PHOTOG AND SF CHRONICLE/NO SALES-MAGS OUT less

LASER18_0143_cs.jpg Event on 6/14/07 in Petaluma.
A focused laser beam machines the interior of a glass prism using a Raydiance laser platform. According to the website of the Petaluma company, Raydiance has is developing the world�s first fully software-controlled, desktop-size ultrashort pulse (USP) laser. Photographed June 14, 2007.
Chris Stewart / San Francisco Chronicle Greg Spooner, Raydiance MANDATORY CREDIT FOR PHOTOG AND SF CHRONICLE/NO SALES-MAGS OUT less

LASER18_0143_cs.jpg Event on 6/14/07 in Petaluma.
A focused laser beam machines the interior of a glass prism using a Raydiance laser platform. According to the website of the Petaluma company, Raydiance has ... more

LASER PRECISION, NO HEAT / Petaluma startup zeroes in on a technology that it hopes will spawn a new industry

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In a quiet industrial park in Petaluma, a startup called Raydiance Inc. is miniaturizing a type of laser that generates an ultrashort burst of photons so intense that it can vaporize matter without creating heat.

Why would anyone want such a device?

CEO Barry Schuler, who founded Raydiance based on technology that arose from military research, says it could be used for any number of purposes, such as removing tattoos without burning the skin or killing cancer cells without affecting healthy ones.

"This company has been in stealth mode for three years," said Schuler, who briefly ran AOL after its merger with Time-Warner. "This technology is so new, so out there and bold, that we didn't know if it would work."

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Now, Schuler is ready to proclaim that the Raydiance laser -- which looks like an ordinary slide projector -- could spawn an industry based on using brief bursts of photons to poke clean holes, with no burn marks, in anything from skin to steel.

"We can manipulate matter," said Schuler, who has raised about $25 million. Raydiance employs about 30 people and plans to roughly double that number within a year.

Raydiance could be the latest sensation in the laser industry, which has been around for decades. Today these focused light beams are used for everyday applications such as reading the data stored on DVDs.

"I've been in lasers since 1962," said Ronald Waynant, a senior optical scientist for the U.S. Food and Drug Administration who has been testing the Raydiance system for medical uses.

As Waynant explained, the Raydiance system is based on a technology called ultrashort pulse lasers.

As the name implies, the duration of the light pulse is extraordinarily brief. In scientific terms, the pulse lasts for mere "femtoseconds" -- each femtosecond being a billionth of a millionth of a second. The time scale defies the imagination, but the idea is easy to grasp.

"You're putting an awful lot of power into a small place in a very short period of time," Waynant said.

What happens when an ultrashort pulse laser hits its target?

To comprehend that, recall that matter is composed of atoms. The classic image of the atom is a tiny replica of the solar system with a nucleus at the center and electrons buzzing around it like so many itty-bitty planets.

All of a sudden the unsuspecting atom is smacked by a swarm of photons that materialize out of nowhere, knocking its electrons out of orbit and causing what scientists call a Coulomb explosion. In plain English, the material seems to vaporize.

Moreover, the pulse is so brief that this disappearing act occurs without creating the heat that normally results when objects collide.

"The electrons are just blown out of the area, vaporizing the material that was in that spot," Waynant said. "What is important is that you don't transfer the heat. It's different than the old lasers with longer pulses, where you used to create a lot of thermal damage."

It is this ability of ultrashort pulse lasers -- to drill or cut matter without burning -- that interests Waynant. He's been using one of the Raydiance devices for about a year to see whether it can do things such as make eye surgery more precise, target cancer cells without collateral damage, or remove tooth decay without drilling.

Although the FDA collaboration is in the early stages, one application for the Raydiance laser is moving toward commercialization.

Silicon Valley entrepreneur Ajit Shah, who among other things helped develop surgical systems for SRI International, is lining up $500,000 in seed funding to start a company called EpiRay. It hopes to use the ultrashort pulse laser to remove tattoos and perform other dermatological operations such as wrinkle removal.

Shah, who was a Raydiance consultant before he decided to use the technology to start a company, said unlike current laser tattoo removal systems, the new device should be able to vaporize the dyes that create the image without burning the skin.

So far that promise is unproven. Shah can't begin testing without FDA oversight and approval, but he hopes the agency's familiarity with medical lasers will expedite the process when he gets funding and is ready to start testing.

Schuler said commercial applications such as EpiRay are central to the company's business plans. As Schuler explains, the innovation at Raydiance is not the ultrashort pulse laser itself. The technology has been around in laboratories for years, and the military has been interested in using it for things like zapping missiles.

But Schuler compared those laboratory systems to big and bulky mainframe computers. He contrasts them to the Raydiance system that fits on a desktop and is controlled by software that minimizes the tweaking and fussing needed to make the ultrashort pulse laser work.

"These ultrashort pulse lasers create unique interactions with matter that have only been done before in university environments," Schuler said. "Now we're making this capability inexpensive. We hope to seed an explosion of innovation."

Schuler said he hopes to create an ecosystem of experimental users who would be to Raydiance as software developers are to the computer industry -- creating new uses for the company's hardware.

Schuler said Raydiance has about 15 systems being tested and evaluated by potential developers. Assuming some of these applications prove technically and commercially feasible, Schuler plans to lease the system for upward of $20,000 a month.

Will there be a market for this hitherto little-known technology that uses photons to dematerialize atoms? Of that Schuler the salesman and visionary has no doubt.

"We're moving into the era of light," he said. "We call it the light age."

PUTTING

ULTRASHORT PULSE LASERS TO WORK

Ultrashort pulse lasers have been around in laboratories since the 1980s. They create brief but incredibly powerful pulses of light, or photons. The beam from an ultrashort pulse laser can instantly vaporize any target without heating it or affecting its surroundings. Raydiance miniaturized this technology and hopes to create new uses, such as tattoo removal or cancer treatment.

Creating the pulse: Ordinary photons are pumped into a ring of fiber-optic cable treated with the rare earth element erbium. When an erbium atom in the fiber cable is struck by a photon, it emits another photon. Repeated collisions and emissions produce a chain reaction to create a beam of very short bursts, or streams, of photons.

Stretching the pulse: The beam is directed through a another device that, like a prism, bends light in such a way as to cause photons of different wavelengths to spread out and march behind one another, rather than side by side.

Amplifying the pulse: The stretched-out beam is sent through another loop of erbium-treated fiber-optic cable to continue the process of amplifying the number and boosting the power of the stream of photons.

Concentrating the pulse: The now high-energy stream of photons that emerges from the amplification stage is recompressed into a single ultrapowerful beam by sending it, in reverse, through the same process that first spread out and separated them.

Properly controlled, the resulting light pulse can strip electrons from the atoms of any material the light pulse strikes, turning the target material into a plasma, or gas-like state.

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